Waste Not, No Lights

Alchemists tried in vain to transmute lead into gold. What if you could turn waste products into energy? That’s what [chemicum] did in a recent video–he and some friends built microbial fuel cells that convert excrement into electricity (you can see the video, below).

The video doesn’t give you all the details of the build, but it seems easy enough. You need some stainless steel mesh, some activated charcoal, some epoxy, plastic containers, and some assorted metal plates and hardware. Of course, you also need excrement and–if the video is any indication–some clothespins to clamp your nose shut as you work.

The resulting cell produced a bit over 800mV at 13mA. You can, of course, add more cells to get more voltage or current. Unlike batteries, fuel cells create power as long as they have a source of fuel. The cells in the video don’t appear to have any way to renew their fuel supply. If you want more detail about bacteria-based fuel cells, there’s always Wikipedia.

This isn’t the first microbial cell we’ve seen (although our favorite had a fish in it). It isn’t even the first cell we’ve seen that converts waste products to power.

19 thoughts on “Waste Not, No Lights

      1. Not quite.
        The top of the column is free to reduce oxygen but anaerobic conditions exist in the bottom. Certain bacteria are able to transport (through special extracellular ‘messenger’ compounds, or through conductive appendages) electrons allowing carbon oxidation where there is no direct access to oxygen.
        They give a quick run down of the relevant reactions in their youtube description but a more verbose version is in this wiki article. https://en.wikipedia.org/wiki/Bacterial_nanowires

        The carbon/steel plates just allow us to tap into this setup.

    1. Given the economies of scale it makes more sense to continue flushing your poo. A central processing plant would be able to monitor chemistry more closely to ensure optimum power generation.
      With the added benefit of letting you pay someone else to wear a clothespin.

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